This invention relates to automotive seat recliners and more particularly, to an infinitely adjustable seat recliner incorporating a spring-type clutch mechanism.
A seat recliner utilizing a spring clutch mechanism of the type contemplated for use in the present invention is described in my co-pending U.S. application, Ser. No. 787,267 filed Oct. 15, 1985. The recliner disclosed therein is provided with an infinitely adjustable seat back made possible by use of a pair of spring coil clutches tandemly mounted on a common spindle having oppositely wound windings which provides for retention of the spindle, and thus the seat back, at a desired angular position against rotational loading in both directions of movement of the seat.
This tandem spring arrangement sharing a common clutch spindle, while effective, has two principle shortcomings. First, the side-by-side arrangement of the clutch springs is not space efficient in that the width of the seat frame side rails must be increased to accommodate the combined width of the two clutches.
Secondly, one clutch absorbs the rotational loading caused by rearwardly directed forces on the seat back due to, for example, inertial forces generated in rear end impacts or user initiated forces, which can be significantly greater than forces imposed on the seat in a forward direction. In the tandem clutch spring arrangement, one spring must be designed to withstand the increase in loading which requires more costly spring and clutch components and precludes interchangeability of the two clutch springs unless one of the springs is over designed, which is also not cost efficient. It can be appreciated that manufacturing costs are thereby significantly increased.